Steam locomotive, including individual axle drives



Oct. 14; 1952 H. NYFFENEGGER 2,613,613

STEAM LOCOMOTIVE, INCLUDING INDIVIDUAL AXLE DRIVES File d March 7, 1945 Patented Oct. 14, 1952 i 11.112. 3.613 I v 7 i j. STEAM ocoMoTwE, INCLUDING? INDIVIDUAL AXLE DRIVES Hans Nyffenegger, Winterthur, Switzerland, assignor to- Schweizerlsche L'okomotiv- "und- Maschinenfabrik, Winterthur, switze'rland Application Ma r ch 7, 1945, Serial No..58:1,'407 1 5 In Switzerland December 18, 1943 Section I, Public Law 690, August 8, 1946 Patent expires December 18, 1963' This invention relates to'locomotives including individual axle drives.

, ,Proposals, and actual constructions of steam locomotives are known in which the driving axles are independently driven by steam engines.

However, allsuch constructions, whether with or without transmission gear, are not fully satiscomplex; Further, the provision of separate flexible couplings between the crank shafts of the engines and the pinion shaftis indispensable.

In another known practical application, two cylinder steam engines with the cylinders arranged in V-shape are disposed on the frame exteriorlybeyond the wheels and are connected with the associated wheel and axle structure by means of a flexible coupling. In this arrangement the speed of revolution of the engine depends exclusively upon the driving wheel diameter and the driving speed, due to the absence of a transmission gear. Further, the driving axle performance is restricted in this arrangement for the reason that, with a view to avoiding excessive wheel bases, it is imperative to associate only one steam engine with each driving axle so that alternate engines are arranged on the right and left hand side of the locomotive respectively. If then, in an effort to raise the engine speed a transmission gear is interposed between the motor and the driving axle the remaining available space for the accommodation of the engine is limited to an objectionable extent. The abovementioned difficulties cannot be eliminated by the use of high steam pressures either. Generally speaking, considerable difiiculty is encountered in building steam locomotives including individual axle drives from the point of view of satisfying all the contradictory requirements in regard to critical speed, compensation of movable masses and uniformity of driving torque.

In the arrangement according to the present invention, the commonly known drawbacks are eliminated as well as the abovesaid difficulties in that each engine crank-case is rigidly secured to 1 Clainnj (01. 105-115) crank-shafts. t a Two embodimentsof the present invention are the transmission gear casing, the transmission- :gear pinion shaft is journaled solely adjacent its ends in the said casing and atits ends are rigidly but-disconnectibly coupled to the piston-engine illustrated, by wayqof example only, in theaccompanying drawings, in which 1 :Fig. lyshows the left-hand portion of the first example, including four engine cylinders and a frame disposed inside the driving-wheel planes,

Fig. 2 a schematic view of .said drive in side elevation; A i Fig. 3 showsa modified detail of Fig. 1, and Fig. 4 shows the left-hand portion of the secand example including six cylinders anda frame disposed outside the; driving-wheel planes.

-Referring to Fig. 1, the-crank shaft l of one of narily rigidly built hollow shaft the central portion of which carries a centrifugal mass 9 adjacent to both end faces of which a pinion i0 is shrunk on the hollow shaft. The bearings 6 which are symmetrically arranged on the hollow shaft relative to the middle plane of the locomotive are, however, not disposed immediately at the side of the pinions in but remote therefrom at both ends of the pinion shaft 8 directly on the side of the coupling flanges 5. The pinion shaft is parted in the middle along a plane H and its two halves are interconnected by means of screws (not shown).

The pinions [0 on the shaft 8 are in mesh with spring mounted gear rims of the gear wheel gears I2 which are arranged on a countershaft I! (Fig. 2) which is mounted in the gear casing 1. Numeral 12a (Figs. 1 and 4) indicates two tangentially arranged springs providing the said springmounting. This countershaft carries a further gear wheel I 3 which cooperates with a large hollow gear wheel M which surrounds the driving axle and is also mounted in the gear casing 1. The hollow gear 14 is connected with the driving axle l5 by means of a flexible coupling which is not shown in detail in the drawings.

The construction shown in Fig. 1, although rangement as shown in Fig. 1 are, advantageous- 1y, relatively offset by 180 or 135 at least. The crank shafts of the two engines are relatively offset by 90.

movable masses. Due to the rigid construction of the pinion shaft 8, this shaft is free from torsional oscillations within the range of computed running, particularly free from the fearedcoun ter oscillations resulting from conjoint oscillation by the two associated steam engines.

With this arrangement the pinion shaft can be satisfactorily supported by bearings which are situated at a great distance apart so that the inner crank shaft bearings can be omitted by virtue of the firm connection between the pinion shaft and the two crank shafts. By this'means the simplest form is obtained for the two steam engines which apart from this have an improved degree of mechanical efiiciency on account of the reduced number of crank shaft bearings. For improving the course of the driving torque curve of the steam engine the central crank arm I 8 can be given the form of an additional centrifugal mass l9, as shown in Fig. 3.

The arrangement illustrated in Fig. 4 differs from that shown in Fig. 1 in that, apart from the employment of an exterior frame 20 instead of an interior frame, three cylinders can be provided instead of two for the steam engines on opposite sides of the locomotive the efficiency of each of which is 50% greater than that of the engines formerly used.

In accordance with the greater number of cylinders the resulting driving torque is more regular compared with that produced by 2 x 2 cylinders. The engine cranks of the three-cylinder engines are relatively oifset by 120". Furthermore, the pinion shaft is composed of three parts joined together by screw connections. If the pinion!!! is in form of a toothed rim and 4 is shrunk on the hollow shaft 8 this arrangement of the pinion shaft permits of making the flanges 4, of a larger diameter than if the shaft were not subdivided at all, for the. reason that then the diameter of these flanges needs no longer 4 to be smaller than the inner diameter ID of the toothed rim of the pinion. Above all, in this exterior frame arrangement, for the wheel and axle structures I5, advantageously, roller bear- This construction further lends itself for a maximum possible equalization of ings can be arranged at 2| instead of friction bearings.

I claim: In a steam locomotive having a main frame,

a plurality'of driving wheel-and-axle sets mounted in said frame, a drive unit for each said set, said unit including two multi-cylinder piston engines having each a crank case and a crank shaft situated exteriorly of said main frame on either side thereof, transmission gearing common to both crank shafts for transmission of torque from the crank shafts to the corresponding wheel-and-axle set, a gear casing rigidly secured to said main frame,'a pinion shaft having opposite ends rigidly coupledeach with one of said crank shafts, said gearing including a primary pinion on said pinion shaft, a gear wheel surrounding the driving axle in driving connection with said pinion, and a flexible torque.transmission coupling between said gear wheel and the driving axle, said crank cases of each. driving unit being directly secured to the respective transmission gear casing.

HANS NYFFENEGGER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 40 Number Name Date.

2,140,967 Nyflenegger Dec'. 20, 1938 2,197,373 Besler et al Apr. 16,1940

FOREIGN PATENTS Number Country Date 609,626 Germany -1- Feb. 19, 1935 200,774 Switzerland Feb. 1', 1939 

